Interview Questions.

Question 1. What Is Gsm?

Answer :

GSM, which stands for Global System for Mobile communications, reigns as the arena’s maximum extensively used cell telephone technology. Cell telephones use a cellular phone provider carrier’s GSM network via trying to find mobile smartphone towers in the close by place. The origins of GSM may be traced returned to 1982 whilst the Groupe Spécial Mobile (GSM) turned into created by means of the European Conference of Postal and Telecommunications Administrations (CEPT) for the cause of designing a pan-European cellular generation.

Question 2. Explain The Services Offered By Gsm?

Answer :

The offerings supplied via GSM are ISDN well suited
GSM lets in synchronous data and asynchronous records to be transported as bearer provider, one of the telecommunication services provided via GSM, and paperwork ISDN terminal
The statistics might be either transparent provider or nontransparent provider
Telephony is one of the offerings supplied through GSM, which an emergency and the provider issuer is notified through dialing 3 digits
By using suitable fax adaptor, G3 fax provider is supported
One of the capabilities of GSM is Short Messaging Service
Certain services, specifically supplementary offerings are provided on top of teleservices or bearer offerings with the aid of GSM, along with, caller identification, call forwarding, multiparty conversations, barring outgoing calls and get in touch with waiting. 
 

Networking Interview Questions
Question three. What Is The Maximum Data Rate Supported By A Gsm System?

Answer :

The most records rate supported with the aid of a GSM gadget is nine.6 kbps.
However there are extensions to GSM preferred to enhance throughput.
GPRS is one of the prolonged GSM provider.
The extended standards of GSM allows theoretical information costs on the order of 114 Kbit/s, but with throughput toward 40Kbit/s in practice. 
Question 4. Does Extended Cell Have Any Impact On The System? If Yes, What?

Answer :

•The cell radius could be double or even extra, primarily based at the antenna, form of terrain and timing boost.
•Indoor insurance is supported through GSM and may be finished with using picocell base station or an indoor repeater together with dispensed indoor antennas.

Networking Tutorial
Question 5. What Do You Mean By Extended Cell?

Answer :

•Extended cellular feature enables the operators for extending the insurance without installing new cellular cites.
•Extended cell function is designed in particular for presenting masking in rural areas, where density of populace is low and set up of extra mobile web sites.
•New capabilities may be deployed in coastal areas for providing GSM coverage in offshore waters.

Mac OS X Deployment Interview Questions
Question 6. Explain Tdd In Gsm Technology?

Answer :

•Time Division Duplexing, a 3GPP standardized version of Universal Mobile Telecommunications System networks.
•The targeted cell sends the records in a stipulated time and gets statistics from the BTS in over again.
•The time is split into various time slots and user sends facts in few time slots and receives the statistics inside the rest of the time slots.
•Alternative downlink and uplink directions are used.

 

Question 7. Explain Fdd In Gsm Technology?

Answer :

•Frequency Division Duplex is one of the strategies, in which one frequency band is applied for transmitting and another used for receiving.
•To up-hyperlink the wearing statistics from mobile telephones to the base station, one electromagnetic block spectrum is allotted.
•Various blocks of spectrum is allocated to down-hyperlink wearing records from the bottom station to the mobile smartphone handsets.

WiMAX Tutorial WiMAX Interview Questions
Question 8. What Is The Mean Of Power Control In Gsm Technology?

Answer :

•Power control is the intelligent choice of transmit energy in a conversation machine for achieving first-rate performance in the gadget.
•The performance is rely on context and there are possibilities to include optimizing metrics like link data price, community capacity, geographic coverage and variety.
•A higher transmit power translates into a better sign strength at the receiver.
•The bit mistakes rate will be reduces at the receiver of a digital conversation hyperlink, by way of having better signal-to-noise ratio.
•Higher transmit electricity affords extra protection towards a signal fade in a wi-fi fading channel.

Question 9. What Do You Mean By Arfcn In Gsm Technology?

Answer :

•Absolute Radio Frequency Channel Number, a code to specify a couple of physical radio companies and channels within the spectrum this is allotted for cell mobile communications.
•ARFCN is used for transmitting and receiving on the UM Interface, one to uplink signal and one to downlink sign.
•ARFCN's bandwidth is 270.833 kHz; channel spacing is two hundred kHz in a given GSM band.
•The uplink-downlink spacing is generally forty five / 50 MHz.
•If Frequency Division Duplex is operated in the system, then the channel number is associated with both uplink and downlink radio channels.
•ARFCN is 1-124 within GSM900 spectrum, 512-885 inside GSM1800, 512-810 within GSM1900, are used.

UMTS Interview Questions
Question 10. Explain Ms-idn In Gsm Technology?

Answer :

•Mobile Subscriber Integrated offerings Digital Network Number, a completely unique wide variety identifying a subscription in a GSM / UMTS mobile network.
•It is the smartphone quantity of the SIM card in a cellular cellphone.
•MSIDN and IMSI are important numbers used to identify a cell subscriber
•MSIDN is used for routing the calls to the subscriber, in which as IMSI identifies the SIM.
•In the HLR, the IMSI is the key, and MSIDN is the number that is dialed for connecting a call to the cell telephone.

UMTS Tutorial
Question eleven. What Is Imei In Gsm Technology?

Answer :

•International Mobile Equipment Identity is more than a few commonly unique for figuring out GSM,WCDMA and iDEN cellular telephones.
•It is normally revealed inside the battery compartment of the cellphone.
•The wide variety can be displayed at the display by using coming into *#06# into the keypad on maximum of the phones.
•A stolen telephone may be stopped from getting access to the network within the u . S ., by means of the usage of IMEI range for legitimate devices.
•Unlike CDMA/MEID's electronic serial variety, the IMEI is simplest used for identifying the device and has no permanent relation to the subscriber
•The subscriber is diagnosed with the aid of IMSI number, saved on the SIM card, which then may be transferred to every other handset.

4G Interview Questions
Question 12. What Is Tmsi In Gsm Technology?

Answer :

•Temporary Mobile Subscriber Identity for maximum usually sent between the mobile and the network.
•TMSI is assigned randomly by VLR to each cellular within the vicinity.
•The TMSI variety is local for a particular local location, and need to be up to date whenever while the cell actions to a new geographical region.
•Paging a cellular is the key use of the TMSI.
•The communication among the mobile and the base station is called paging.
•The emphasis of broadcast records is pinnacle installation channels for paging.
•Broadcast mechanism is to be had in every cell machine for distributing broadcast records to a plurality of mobiles.

Networking Interview Questions
Question 13. Explain Imsi In Gsm Technology?

Answer :

•International Mobile Subscriber Identity - a completely unique identity this is related to all GSM and UMTS community cellular telephones.
•The SIM inside the cellphone contains it as a 64 bit area.
•Used for obtaining certain info in Home Location Register or Visitor Location Register.
•IMSI is rarely despatched for stopping eavesdroppers to perceive and music the subscriber on the radio interface.
•It is presented as 15 digit long wide variety, wherein first three digits represent the Mobile Country Code and observed by means of the Mobile Network Code.
•Remaining digits are cell station identification quantity in the client base community.

CDMA Tutorial
Question 14. What Is Gos In Gsm Technology?

Answer :

•Grade of Service is a chance of a cellular in a circuit organization which is blocked / not on time for extra than a unique c language.
•GoS is expressed as a vulgar fraction / decimal fraction.
•It is with regards to the busy hour on the time of finest depth of the traffic.
•GoS can be regarded independently from the perspective of incoming vs outgoing calls.
•The GoS is not essentially equal among supply to vacation spot pairs.

Question 15. What Is Erlangs In Gsm Technology?

Answer :

•Total visitors extent in keeping with hour / 3600 seconds is described with the aid of erlang
•For example, 60 calls in one hour and every lasting five mins consequences the subsequent:
Minutes of traffic in an hour = Number of calls x Duration
Minutes of traffic in an hour = 60 x five = 300 mins
Hours of traffic inside the hour = three hundred / 60 = five hrs
The visitors figure = five erlangs

Wideband Code Division Multiple Access (WCDMA) Interview Questions
Question 16. What Is Trx In Gsm Technology?

Answer :

•The transceivers allows to serve several frequencies and distinctive sectors of the mobile.
•Sends and receives alerts from / to higher network entities.

LTE Tutorial
Question 17. What Is Drx In Gsm Technology?

Answer :

•DRX is referred as driver receiver.
•DRX performs the transmission and reception of indicators.
•Sends and receives the signals to or from higher community entities, as in base station controller in cell telephony.

 

3G Interview Questions
Question 18. What Is Dtx In Gsm Technology?

Answer :

•Discontinuous Transmission is one of the strategies which is based at the advantage of the fact that someone communicate much less
•Nearly forty% of time in widespread conversation, the transmitter is became off in the course of silence durations
•Mobile phone strength conservation is an delivered advantage of DTX
•Voice Activity Detection is the most important component of DTX
•DT X distinguishes between voice and noise inputs.
•The transmitter is turned off while a voice sign is misinterpreted as noise. This reasons worrying effect referred to as clipping is heard on the receiver's stop
•Comfort noise is created at the receiving give up, so as to make sure the non-connection.

Mac OS X Deployment Interview Questions
Question 19. What Is Hsn In Gsm Technology?

Answer :

•Hopping sequence wide variety is applied, to spread the interference between all cells that makes use of the equal hopping TCHs.
•The correlation between carefully placed cells can be averted through the use of HSN.
•HSN of zero corresponds to the cyclic hopping sequence, and 1 through 63 corresponds to diverse pseudo random styles.

Question 20. What Is Cycling Frequency Hopping In Gsm Technology?

Answer :

•In Cycling Frequency Hopping, the frequencies are changed, in every TDMA body.
•For ex: f1,f2,f3 …. Where f1,f2,f3 are frequency hopping sequence numbers
•The detailed placing parameter is HSN.
•Hopping Sequence Number is about to 0 in a cyclic series hopping.
•The collection of frequencies begins from the bottom absolute frequency variety in a hard and fast of frequencies detailed for a particular channel institution, to maximum absolute frequency number.

Progress 4GL Interview Questions
Question 21. What Is Base Band Frequency Hopping In Gsm Technology?

Answer :

•Base Band Frequency Hopping is one of the frequency hopping strategies.
•Time department multiplexing mapping is utilized in BBFH
•BBFH is supported by way of a base station having a broadband transceiver
•Physical channels are accredited by BBFH primarily based upon cell subscribers' communique with the bottom station.
•In this, static transceiver frequencies are used even as running with broadband transceiver. This method is an special of switching conversation signals among transceivers.

Question 22. What Is Synthesised Frequency Hopping In Gsm Technology?

Answer :

•The GSM's quantity of frequencies is 124
•When the operators do no longer have sufficient frequencies, the variety to be used is CDS 1800
•Frequency hopping is used while the frequencies used are extra with excessive interference.
•Frequency hopping is applied to equalize interference for the frequencies which can be used in their variety.
•One of the frequency hoppings is Synthesised Frequency Hopping
•Synthesized hopping permits the transmitter to exchange its frequency based totally on time slots. Because of this method SFH is known as rapid hopping.

Question 23. What Is Maio In Gsm Technology?

Answer :

•Mobile Allocation Index Offset is applied to same timeslot of different TRX.
•Every time slot may have a separate / special MAIO, as they are the use of the same HSN
•In case all time slot have the same HSN, a their sequence want to be started at one-of-a-kind frequencies
•The MAIO will set the index of the sequence for every timeslot.
•The HSNs do no longer run the same pseudo random series on the identical second.

Adobe Edge Interview Questions
Question 24. What Is Ma In Gsm Technology?

Answer :

•The Absolute Radio Frequency Carrier Number is utilized in hopping series sample are decided by sure contents of the check set's Mobile Allocation Table.
•The hopping collection beginning point is known as Mobile Allocation Index Offset.
•The first access of Mobile Allocation is corresponds to 0.
•An MA desk is a listing of ARFCNs. They found in Cell Allocation Table which stocks the equal frequency band.
•A separate MA desk is allotted for each frequency band.

WiMAX Interview Questions
Question 25. What Is Wps In Gsm Technology?

Answer :

•The wi-fi equal of the Government Emergency Telecommunications Services is stated WPS.
•WPS provides get right of entry to based on the priority to wi-fi phone provider throughout emergencies
•Certain governing our bodies together with authorized federal, officers of kingdom and neighborhood, and positive key private area officers may be positioned first in line for an open mobile channel by way of dialing 272 simply earlier than coming into the range being referred to as
•It is T-Mobile, which began providing an preliminary running functionality in New York and Washington and had it deployed later.

Question 26. What Is Cell Splitting In Gsm Technology?

Answer :

•The procedure of dividing the radio coverage of a cellular website online within a wireless cellphone machine into new cell websites is referred to as Cell Splitting
•Additional capability within the region may be done by using using Cell Splitting

CDMA Interview Questions
Question 27. Do You Know What Is Frequency Re-use?

Answer :

•Frequency Reuse is one of the strategies for improving capability and spectral performance
•Commercial wi-fi systems are based on Frequency Reuse, that includes the partitioning of an RF radiation location into mobile segments.
•A frequency that is far enough away from the frequency inside the bordering section is used by one phase of the cell.
•Similar frequency is used at the least  cells apart from every other.
•This exercise allows various mobile providers to have several customers for a given website online license.

UMTS Interview Questions
Question 28. What Is Channel Coding In Gsm Technology?

Answer :

•The facts fee for the radio channel is 270 kbps
•The data fee is cut up into eight full charge or 16 half price site visitors channels, at the side of signaling channels
•In order to have the most threat for detecting and correcting mistakes, the code is complex in a standard propagation path
•Forward Error Correction is carried out with a view to get the speech coder encryption, coding and interleaving in a sophisticated manner
•The data is sent as bursts in 577 mus time slots. Each includes 116 encrypted bits
•Every TDMA frame consists of 8 or sixteen time slots
•Transmit time slots are staggered, in order that at a few on the spot the mobile station will not receive the equal instants while transmitting, which enables the simplifying the filtering necessities
•At least one spare slot among transmit and get hold of is to be had with this scheme.

Question 29. What Is Speech Coding In Gsm Technology?

Answer :

•Speech coding is all approximately turning voice into digital shape
•Speech is inherently analog, as GSM is a digital system.
•The digitization is hired through ISDN, and the modern phone systems which might be used for multiplexing voice strains, with high speed trunks, optical fiber lines is carried out with the aid of Pulse Code Modulation(PCM)
•The PCM output is sixty four kbps, that's too excessive over a radio link in feasibility
•The 64 kbps signal is redundant
•The set of rules used in traditional cellular is Vector Sum Excited Linear Predictive speech compression.

LTE Interview Questions
Question 30. What Is Interleaving In Gsm Technology?

Answer :

•Time diversity in a sign communique gadget is obtained by way of using Interleaving.
•The opportunity of dropping entire bursts might be reduced by using interleaving
•Total 456 bits from convolution encoder, consisting of 20ms of speech, is subdivided into 8 blocks. Each block includes fifty seven bits.
•All those blocks are transmitted in consecutive time slots.
•Enough data is to be had in 7 blocks, in case one of the blocks is misplaced due to burst mistakes. This allows whole section restoration by means of the usage of blunders correction.

Question 31. What Is Equalisation In Gsm Technology?

Answer :

•An adaptive equalizer is employed with the aid of a GSM receiver for overcoming the impact of non-perfect channel characteristics which are due to multipath propagation. 
•Adaptive equalizer is required because the channel characteristics are frequently converting rapid. 
•Tuning the for on every occasion slot is executed by using the equalizer.

Question 32. Name The Algorithms Used In Following? A. Ciphering  B. Authentication

Answer :

•Ciphering : The set of rules 129-EEA3 and 128-EIA3, 3GPP Confidentiality and Integrity Algorithm is used for ciphering in GSM 
•Authentication : The set of rules through name A3 is used for authentication within the GSM structures 
This set of rules is utilized in implementing Subscriber Identity Module.

 

LTE Rf Planning Optimization For 4g Interview Questions
Question 33. Which Up-hyperlink/ Down-hyperlink Spectrum Is Allocated To Following? A. Gsm - 900 B. Dcs - 1800

Answer :

•GSM - 900: Up-link spectrum is 890.2-914.Eight and down-link spectrum is 935.2-959.Eight

•DCS - 1800: Up-hyperlink spectrum is 1710.2-1784.Eight, and down-link spectrum is 1805.2-1879.Eight

4G Interview Questions
Question 34. What Is Discontinuous Transmission In Gsm Technology?

Answer :

•Discontinuous Transmission, additionally referred to as DTX in quick is a way of momentarily powering down a mobile set while there may be no voice enter to the set.
•The typical performance of a wi-fi voice communique machine is optimized via DTX.
•Each speaker in a two way verbal exchange speaks barely less than half of of the time.
•The workload of the additives inside the transmitter amplifiers are made smooth and reduces interference.

Question 35. What Is Transmitted Power Control In Gsm Technology?

Answer :

•Transmitted energy manipulate is one of the technical mechanism used inside some networking gadgets
•TPC is used for stopping an excessive amount of undesirable interference among wireless networks
•The vital concept is to routinely reduce the transmission output strength used, whilst different networks are inside the same range.
•TPC reduces interference issues and increases the battery capacity
•The electricity ranges of a single mobile device may be decreased with the aid of 6dB

Question 36. What Is Frequency Re-use In Gsm Technology?

Answer :

•Frequency re-use is the key component of cellular community capability for increasing both coverage and capability.
•Different frequencies are utilized by adjoining cells; however trouble does no longer rise up to determine the cell sufficiently far apart the usage of the same frequency.
•Reuse distance and the reuse component are the two elements that have an effect on frequency re usability
•The frequency is 1/K, where K is the number of cells that can't use the identical frequencies for transmission.

Wideband Code Division Multiple Access (WCDMA) Interview Questions
Question 37. What Is Sectorization Of A Cell In Gsm Technology?

Answer :

•Sectorization is a procedure to reduce down system fees in a cellular community. It affects in traffic load and mobile length
•Sectorization reduces co-channel interference, when carried out to clusters of cells
•The most traffic capability of area-ed antennas is more than omni directional antennas.

Question 38. Explain The Maximum Data Rate Supported By A Gsm System?

Answer :

The maximum records charge supported through a GSM system is 9.6 kbps.
However there are extensions to GSM preferred to improve throughput.
GPRS is one of the extended GSM service.The prolonged requirements of GSM lets in theoretical facts rates at the order of 114 Kbit/s, however with
throughput closer to 40Kbit/s in practice.

 

Question 39. What Are The Services Offered By Gsm Technology?

Answer :

•The offerings provided by GSM are ISDN compatible
•GSM permits synchronous information and asynchronous statistics to be transported as bearer carrier, one of the telecommunication offerings supplied by way of GSM, and paperwork ISDN terminal
•The facts may be both transparent service or nontransparent provider
•Telephony is one of the services offered by means of GSM, which an emergency and the service company is notified with the aid of dialing three digits
•By the usage of appropriate fax adapter, G3 fax provider is supported
•One of the features of GSM is Short Messaging Service
•Certain offerings, particularly supplementary services are furnished on top of tele services or bearer offerings by way of GSM, including, caller identity, call forwarding, multiparty conversations, barring outgoing calls and get in touch with ready.

 

Question 40. Do You Know What Is Gsm Technology?

Answer :

•Short form of Global System for Mobile Communications, is a wireless network device
•A fashionable for virtual cell cell communications
•International roaming preparations are enabled amongst cellular community operators, through supplying the subscribers to apply their personal cell phones anywhere within the world.
•GSM is taken into consideration as second technology cellular, as signaling and speech channels are virtual
•The carriers can be changed without replacing cell phones.
•The ubiquity of GSM implementations is likewise permitting the switching between community operators, who can pick out gadget from many GSM equipment companies.
•GSM pioneered low fee SMS implementation
•The GSM fashionable consists of a international emergency telephone number function.

3G Interview Questions
Question forty one. What Is The Ssi?

Answer :

Small-scale integration; the manner of concentrating semiconductor devices in a single included circuit.

Question forty two. What Are The Various Blocks In Gsm Architecture?

Answer :

These are the numerous block in gsm structure -
1)BSS-Base Station Subsystem
a.MS
b.BTS
c.BSC
2)NSS-Network Swithing Subsystem
a.HLR
b.VLR
c.AUC
d.MSC
e.OMC
3)Public Network
a.PSTN
b.ISDN
c.Data Networks

 

Progress 4GL Interview Questions
Question forty three. Which Is The Digital Modulation Used Today In Telecom?

Answer :

Currently the virtual modulation used in telecom is GSMK GMSK is a form of modulation used in style of digitalradio conversation structures.It has an advantage4s of being able to deliver virtual modulation at the same time as nonetheless the use of the spectrum successfully.One of the problems with other kinds of phase shift keying is that the sidebands expand outwards from the main provider and this may motive interference to the opposite radio conversation structures using close by channels.

 

Question 44. What Is The Main Difference Between Gsm And Cdma?

Answer :

The primary difference between GSM and CDMA is: In GSM, the whole frequency band isn't always to be had to the stop-person, whilst in CDMA the complete frequency band is to be had to the quit-consumer. So, the Frequency Re-use issue is 1 in CDMA. 

GSM Works as follows:The complete frequency band is divided into chunks and each such bite is divided into timeslots and each such 

portion is made available to a person. 

CDMA Works as follows:The entire frequency band is to be had to the person. So, in an effort to differentiate, the transmission from each consumer 

is "spread" or coded the use of an precise code given to man or woman person. At the receiving give up, the unfold facts is decoded.

Question forty five. Explain What Is The Relation Between Rxlev [0 To 63] And Rxlev [-110 To -47]?

Answer :

Rx degree 0 to 63 is GSM unit. While -one hundred ten to -47 is dbm 
Rxlevel unit of GSM. When we are able to add a hundred and ten to Rxlevel
[dbm],it'll get convert into GSM unit zero to sixty three.